1870.] CAOADIAN FOSSIL OSTRACODA. 387 



and Leda truncata, both also Scotch fossils. The associated 

 Ostracoda are: 



Cj'there emarginata Sars. 

 Cytheridea Sorbyana Joues. 

 Cytheropteron inflatuin B., C, aud R., MS. 

 Sclerochilus coutortus Normau. 



Montreal. — Upon examining catalogues given by Dr. Dawson 

 in the Canadian Naturalist, it appears that out of 20 species of 

 LamelUhmnchiata, 15 occur fossil in Scotland, and 17 out of 27 

 species of Gasteropoda. The beds contain nearly all the most 

 characteristic Scotch glacial fossils. The associated Ostracoda are : 



Cy there MacChesneyi, nor. sp. Cytheridea Sorbyana (Jones). 



" Dawsoni Brady. Cytherura Robertsoni Brady. 



" globulifera Brady. Cytheropteron complauatum.nov.sp. 



" Logani, nov. sp. " inflatum B., C. and R., MS. 



Cytheridea papillosa Bosquet. " angulatum B., C, audR. MS. 



" puuctiliata (Brady). Encythere argus. 



There is no doubt both that many more species of Ostracoda 

 will be discovered upon examination of larger quantities of 

 material than we have yet obtained, and that the number of 

 Mollusca will be increased by every fresh exposure of the clays ; 

 but these lists have been given, merely tentatively to indicate 

 general relationships, which, when further developed, may prove 

 of geological value in classifying the various deposits of the Glacial 

 epoch. 



One of the writers of this paper (Mr. Brady) has described 29 

 species of recent Ostracoda from the Gulf of St. Lawrence, dredQ;ed 

 in depths varying from 10 to 50 fathoms, but in one case 250 

 fathoms (Annals and Mag. Nat. Hist., Dec, 1870). Of these 29 

 species, 13 are found in our list of fossils from the American glacial 

 clays, viz. : 



Cythere leioderma. Cytheridea papillosa. 

 " lutea. " punctillata. 



" emarginata. Eucythere argus. 



" concinna. Xestoleberis depressa. 



" dunelmensis. Cytherura undata. 



" Dawsoni. Cytheropteron nodosum. 



Although, as Mr. Brady remarks, it is unwise to generalize 

 hastily, yet we cannot help noticing that the general facies of the 

 recent Ostracoda from the Gulf of St. Lawrence much more nearly 

 approaches to that of the Shetland seas or of the Scottish glacial 

 clays, than it does to that of England, while it has scarcely any- 



